1. Field of the Disclosure
The present disclosure relates to a semiconductor laser diode, and more particularly, to a side light emitting type semiconductor laser diode including a dielectric layer formed on an active layer, and a p-conductive layer supplying current to both sides of the dielectric layer and a method of manufacturing the same.
2. Description of the Related Art
Semiconductor laser diodes, currently used in light sources of various information processing apparatuses, require high light extraction efficiency versus an applied electric power to increase information density. Accordingly, research into the optimization of the structure of a laser diode has been conducted.
FIG. 1 is a cross-sectional view of a conventional semiconductor laser diode. Referring to FIG. 1, an n-AlGaN layer 11 is formed on a substrate 10 and an n-AlGaN clad layer 12, an InGaN active layer 13 having a Multi Quantum Wall (MQW) structure, a p-AlGaN clad layer 14, a p-contact layer 15 and a p-electrode layer 16 are sequentially formed on the n-AlGaN layer 11. In addition, an n-electrode layer 17 is formed on the region of the n-AlGaN layer 11 in a region where the n-AlGaN clad layer 12 is not formed.
In order to form the semiconductor laser diode illustrated in FIG. 1, the n-AlGaN clad layer 12, the InGaN MQW active layer 13, the p-AlGaN clad layer 14, the p-contact layer 15 and the p-electrode layer 16 are sequentially formed on the n-AlGaN layer 11. Then, semiconductor materials are removed from the region of the n-AlGaN layer 11 where the n-electrode layer 17 is to be formed to expose the n-AlGaN layer 11, and then the n-electrode layer 17 is formed.
The conventional semiconductor laser diode illustrated in FIG. 1 has the following problems.
First, in the process of forming the semiconductor laser diode shown in FIG. 1, while heat-treatment of the p-AlGaN clad layer 14 is performed at a high temperature in a growth process, segregation of indium (In) grown at a low temperature is performed in the InGaN active layer 13 and thus, the quality of the MQW structure of the InGaN active layer 13 may decline.
Second, doping materials using p-type impurities, for example, Mg, may cause a lattice defect of the p-AlGaN clad layer 14, and thus optical loss is increased.
Third, due to diffusion of Mg in the p-AlGaN clad layer 14, the quality of the MQW structure in the InGaN active layer 13 may decline.